Recently, as a technique of transmitting signals inside a system apparatus, between system apparatuses or between optical modules at high speed, so-called optical interconnection is widely adopted. Here, optical interconnection refers to a technique of handling optical components as if they were electrical components, and mounting them on, for example, a mother board or circuit substrate used for a personal computer, vehicle, optical transceiver and the like.
An optical module used for such optical interconnection has various uses for internal connection of a media converter or switching hub, connection of components inside an apparatus or between apparatuses such as optical transceivers, medical equipment, test devices, video systems and high speed computer clusters.
With an optical module of this type, communication information is transmitted through optical fibers by coupling light which includes communication information and which has been emitted from light emitting elements, to the end surfaces of optical fibers through lenses.
Here, conventionally, it has been pointed out that, with the optical module of this type, the output performance of light emitting elements for emitting light changes due to the influence of, for example, temperature, and therefore there is a risk of disrupting adequate transmission of communication information.
So far, proposals have been made as to various techniques for monitoring light (particularly the intensity or the amount of light) emitted from light emitting elements in order to stabilize the output performance of the light emitting elements.
For example, Patent Literature 1 discloses an optical element that has, around the lens surface (i.e. transmission surface part), a reflecting surface (i.e. reflecting surface part) for reflecting part of light emitted from light emitting elements toward light receiving elements.
Further, Patent Literature 2 discloses an optical module that reflects part of light emitted from laser sources as monitor light by a multi-interface beam splitter, and receives reflected monitor light in a detector.